From c6c8f47b432616b1469c6fc7b03246f3f3c08fa2 Mon Sep 17 00:00:00 2001
From: Peter Hutterer <peter.hutterer@who-t.net>
Date: Mon, 11 May 2026 11:37:14 +1000
Subject: [PATCH] util: add a steal_fd() helper function

We can't use steal for fds because of the -1 requirement.

Assisted-by: Claude:claude-opus-4-6
Part-of: <https://gitlab.freedesktop.org/libinput/libei/-/merge_requests/388>
---
 src/util-mem.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/util-mem.h b/src/util-mem.h
index bacc708..7271f6f 100644
--- a/src/util-mem.h
+++ b/src/util-mem.h
@@ -96,6 +96,21 @@ _steal(void *ptr)
 #define steal(ptr_) \
   (typeof(*ptr_))_steal(ptr_)
 
+/**
+ * Resets the pointer content to -1 and returns
+ * the original value.
+ */
+static inline int
+steal_fd(int *ptr)
+{
+	if (ptr) {
+		int original = *ptr;
+		*ptr = -1;
+		return original;
+	}
+	return -1;
+}
+
 /**
  * Never-failing calloc with a size limit check.
  */